Between the primary and secondary rainbows, there is a dark band known as Alexandar's dark, this forms due to light scattered into this region interfere destructively. Since, primary and secondary rainbows subtends an angle nearly $41^{\circ}$ to $42^{\circ}$ and $51^{\circ}$ to $54^{\circ}$ respectively at observer's eye w.r.t. incident light ray. Then, the scattered rays with respect to the incident ray of the sun lies between approximately $42^{\circ}$ and $50^{\circ}$.